Slightly off topic here but hey this is LZ.
here goes.
If you want to
reliably pull a boat through water, or get up a mountain pass or across a boggy field you dont want a Disco2.
There is a number of electrical faults with Disco2's that will cost you alot to repair and maintain.
I think i would be looking at a nissan patrol or a toyota land cruiser myself.
Certainly not moving from a 300tdi engine to a TD5 thats full of electrics to tow boats.
Anyway. To sell it.
eBay is your widest audience, by a country mile.
Try classic car sites.
maybe even pistonheads and auto trader.